The present invention relates to autobrake systems for aircraft, and more particularly to fuzzy logic utilized for improved control of aircraft autobrake systems.
Fuzzy logic as applied to control systems is exemplified in the patent literature by, e.g., U.S. Pat. No. 4,842,342 to Takahashi, et al., which describes a vehicle antiskid system (i.e., a system used to control braking on a single wheel in such a manner that the wheel lockup is prevented) based on fuzzy control.
Further illustrative of the use of fuzzy logic is U.S. Pat. No. 5,001,640 to Matsumoto, et al., which also describes a vehicle antiskid system. The system is also based on fuzzy inference using a pressure measurement to estimate vehicle deceleration. The system uses a combination of vehicle deceleration, wheel velocity, and wheel deceleration as a basis for control.
In contrast to the aforementioned U.S. Pat. No. 4,842,342 and 5,001,640, the present control objective is different, viz., automatic application and control to a constant deceleration, as opposed to preventing wheel lockup and optimizing braking force. Also, in the present invention, membership functions and rule bases are different.